I did a search before posting and found one other thread on this topic. My situation differs, I think.

Up until last weekend, I only rode SS mountain, geared mountain, and a fixed gear road bike(47x16). 100 miles a week is normal for me either on or off road.

I just completed a rebuild of an old steel geared road bike that I have never ridden previously. I am riding this new bike with new shoes, the road version Sidi's which are identical to the mountain Sidi's I have been using for about a year. pedals are speedplay zeros set for almost max float.

Last weekend I rode 50+ miles Sat and 65+ miles Sunday with no issues at all on the new road bike. Tuesday I rode the West End ride and then Thursday on the West End ride my Achilles started hurting. I actually felt it right after putting on the sidi's before the ride. At the end of the ride I felt pretty good, no discomfort. During the ride, I pushed my foot a little forward in the shoe to relieve some pressure off the back of the heel and that seemed to help. Before leaving I did not tighten the top strap with as much force to see if that was the problem.

All felt good till I put my shoes on for work this morning and the discomfort came back. I don't feel anything unless there is something pressing on the back of my heel. I have full range of motion and no discomfort with shoes off.

Thanks for listening to this long write up, thought you might like the background. FYI, I prefer spinning 90+ on my geared bikes.

"I rode 50+ miles Sat and 65+ miles Sunday with no issues at all on the new road bike. Tuesday I rode the West End ride and then Thursday on the West End ride my Achilles started hurting."

You pushed the miles up in a hustle, likely doubling your weekly miles in a span of 6 days. Rest that tendon for at least two weeks. Ace wrap the ankle to keep the swelling down and do some local cold application for 15 minutes at a time 2-3 times a day for a day or two then switch to warm soaks in similar time frames. Start back on your geared bike, keep the gearing low and the RPM up. Check your saddle height on your new bike setup to make sure you have not gotten the saddle too high or too far back from what you ride on your other road bike set up which could also cause undo strain on the Achilles tendon. When you get back on your bike use the rule of 10: do not push your millage or intensity up more than 10% each week to allow your body time to adjust. Also give your body a rest day after an intense ride day. It's okay to ride your geared bikes for your aging body. Riding will keep you younger but be forgiving to your aging joints and tendons. I never looked back after putting a triple chainring on my road bike, my knees are extermely grateful for it to this day.

In a ddition to the good advice you have recieved from doc nolan I would add you may also be suffering from either retro(behind) calcaneal or achilles bursitis. I offer this as if the achilles were the primary cause of your pain you would have pain with any motion. These bursae are fluid filled sacks that sit in front of and behind the achilles and serve as like airbags to protect the achilles against pressure form the heel bone and external pressure. This pressure could be from your achilles pushing up against the heel bone as your foot bend up as you push down, which could benfit from a seat hieght adjustment or from your shoes pressing from the outside. So in addition to you correcting your training errors look at your seat hieght and your shoe fit.

Thanks, good info. Sounds like that very well may be the case with me since I have no discomfort till there is something pressing against the heel.

Great advice, but where can I go to check if there is a shoe issue? I am using the same brand, sidi, with the same size on my mountain shoe. I already admit to over-tightening the buckle strap on a couple rides. I think this is a big contributing factor to the injury.